Sable · Question
What is the difference between PT-141 and Semax?
PT-141 is a cyclic heptapeptide melanocortin receptor agonist, a metabolite-like analogue of Melanotan II with a C-terminal acid, used in melanocortin receptor research (cyclic peptide, MW about 1025.2 g/mol).
Research use only. Not for human consumption. No health claims.
Last verified 2026-10-10
What is the difference between PT-141 and Semax?
PT-141 is a cyclic heptapeptide melanocortin receptor agonist, a metabolite-like analogue of Melanotan II with a C-terminal acid, used in melanocortin receptor research (cyclic peptide, MW about 1025.2 g/mol).
Which is heavier, PT-141 or Semax?
PT-141 has a molecular weight of about 1025.2 g/mol and Semax about 813.9 g/mol (PubChem), so PT-141 is heavier by 211.3 g/mol, a ratio of 1.26. This means 1 mg of PT-141 contains 975.4 nmol versus 1,228.7 nmol for Semax.
How many mg of Semax are equimolar to 1 mg of PT-141?
1 mg of PT-141 (MW 1025.2) is 975.4 nmol. The same number of moles of Semax (MW 813.9) weighs 0.7939 mg. Equimolar comparisons matter when testing two compounds side by side in the same assay.
Compare the molecular formulas of PT-141 and Semax
PubChem lists PT-141 as C50H68N14O10 (1025.2 g/mol) and Semax as C37H51N9O10S (813.9 g/mol). PT-141 is a cyclic peptide; Semax is a peptide. These formulas refer to the parent compounds without salt counter-ions.
A 10 mg vial of PT-141 equals how many mg of Semax in moles?
10 mg of PT-141 (MW 1025.2) is 9.754 µmol. The same amount of Semax (MW 813.9) would weigh 7.939 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 5 mg vial of PT-141 equals how many mg of Semax in moles?
5 mg of PT-141 (MW 1025.2) is 4.877 µmol. The same amount of Semax (MW 813.9) would weigh 3.969 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 5 mg vial of Semax equals how many mg of PT-141 in moles?
5 mg of Semax (MW 813.9) is 6.143 µmol. The same amount of PT-141 (MW 1025.2) would weigh 6.298 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 10 mg vial of Semax equals how many mg of PT-141 in moles?
10 mg of Semax (MW 813.9) is 12.287 µmol. The same amount of PT-141 (MW 1025.2) would weigh 12.596 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 30 mg vial of Semax equals how many mg of PT-141 in moles?
30 mg of Semax (MW 813.9) is 36.86 µmol. The same amount of PT-141 (MW 1025.2) would weigh 37.788 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A CoA for every lot; each vial carries a printed lot number that matches it. Ask with the lot number and we send it.
Cite this
Research use only. Not for consumption. No health claims.
Plain
Sable Peptides. (2026). What is the difference between PT-141 and Semax?. UK Research Peptide Reference. Retrieved 11 October 2026, from https://www.sablepeptides.co.uk/questions/compare/pt-141-vs-semax/#sqa-040452
APA
Sable Peptides. (2026, October 11). *What is the difference between PT-141 and Semax?*. UK Research Peptide Reference. https://www.sablepeptides.co.uk/questions/compare/pt-141-vs-semax/#sqa-040452
BibTeX
@misc{sable_#sqa-040452_2026,
author = {{Sable Peptides}},
title = {{What is the difference between PT-141 and Semax?}},
year = {2026},
howpublished = {\url{https://www.sablepeptides.co.uk/questions/compare/pt-141-vs-semax/#sqa-040452}},
note = {Accessed 11 October 2026. CC BY 4.0}
}Badge
<a href="https://www.sablepeptides.co.uk/ref"><img src="https://www.sablepeptides.co.uk/badge/ref.svg" alt="Data: UK Research Peptide Reference — Sable Peptides" width="220" height="40"></a>
Date modified: 2026-10-10